Die casting machine



March l5, 1966 w. E. THOMPSON 3,239,896

DIE CASTING MACHINE Filed Dec. 5, 1962 2 Sheets-Sheet 1 A TTOR/VE Y March l5, 1966 w. E. THOMPSON DIE CASTING MACHINE 2 Sheets-Sheet 2 Filed Dec. 5, 1962 United States Patent O 3,239,896 DIE CASTING MACHINE William E. Thompson, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Dec. 3, 1962, Ser. No. 241,770 9 Claims. (Cl. 22-70) This invention relates generally to die casting machines of the hot chamber type and more particularly to improvements in the means for coupling the shot piston to the hydraulic means for operating the shot piston.

A die casting machine of the hot chamber type generally consists of a horizontally disposed structure including an ejector die mounted for horizontally reciprocable movement and a cover die to which a pressure chamber submerged in a mass of molten metal is connected by means of a so-called gooseneck. The pressure chamber includes a shot piston for forcing molten metal under a relatively high pressure Ifrom the pressure charnber to the sprue of the cove-r die. Typically this apparatus includes a vertically positioned stationary die support, a plurality of spaced rods secured to one side of the die support on which there is mounted for reciprocal movement a movable die support member, and a cover die is mounted on the rod side of the stationary die support and an ejector die is mounted -on the movable support on the side facing the cover die. Hydraulic means connected to a toggle mechanism connected to the movable die support is employed to move the movable die suppo-rt reciprocably to and from the stationary die support whereby the cover and ejector dies may be opened and closed in accordan-ce with the die casting cycle.

On the opposite side of the stationary die there is positioned a furnace carrying a pot of molten metal. A pressure chamber having an upwardly extending conduit from the base thereof, typically referred to as a gooseneck, is submerged in the molten metal of the pot and supported so that the mouth of the gooseneck communicates with the sprue of the cover die through suitable nozzle means extending through a suitable opening in the stationary die. Typically, the pressure chamber is supported on a frame mounted on a pair of spaced rods extending horizontally from the stationary die support member and rigidly fastened thereto. Positioned over the pressure chamber there is a hydraulic cylinder operating means connected to the shot plunger of the pressure chamber. This invention is concerned with the means for connecting the shot plunger with the hydraulic means for operating it. Apparatus to which this invention pertains is disclosed in the co-pending patent application Serial No. 241,771, William E. Thompson, filed concurrently herewith and assigned to the assignee of the present invention.

It is the object of this invention to provide an improved means for connecting the shot plunger of a hot chamber type die casting machine with hydraulic means for operating the shot plunger whereby the shot plunger and hydraulic operating mechanism may be arrested in a fixed -position and the shot plunger may be readily installed in or removed from the apparatus whereby alignment accuracy may be readily inspected. It is a more specific object of this invention to provide a coupling means which is permanently fastened to the connecting rod of the hydraulic means for operating the shot plunger and which includes a lower hinged section which may be readily opened to permit the `shot plunge-r to be raised while maintaining the coupling in a fixed position whereby the plunger may be removed from the pressure chamber and installed therein while the coupling and hydraulic operating means is held in a fixed position and whereby the alignment of the shot plunger and the connecting rod of 3,239,395 Patented Mar. 15, 1966 the hydraulic operating means may be visually observed.

yOther objects and advantages will be apparent from the following description thereof, reference being made to the drawings, in which:

FIGURE 1 is a perspective view in partial cross section of die casting apparatus embodying the invention;

FIGURE 2 is a fragmentary cross-sectional view taken along the line 2--2 of FIGURE l;

FIGURE 3 is an exploded view of a c-oupling of this invention; and

'FIGURE 4 is a plan View of the coupling in an operative position.

Referring to the drawings by reference characters, apparatus in connection with which the coupling mechanism of this invention may -be used includes a base 10 extend- :ing beneath the entire die casting machine. Extending from and rigidly secured to the base 10 is a stationary die support .12 which has a plurality of rods 14, four in number, rigidly attached thereto and extending in the direction of the movable die support member 16. These rods are fastened to another stationary support (not shown) at their opposite ends in a well known manner. The movlable die support or platen 16 is slidably supported on the rods 14 and is reciprocably movable toward the stationary die support 12. The stationary die support carries the cover die 18 fastened thereto by suitable clamps 20. The movable die support 16 carries an ejector die 22 fastened thereto by means of the clamps 24. The movable die support 16 also carries an ejector bar arrangement 26 which functions in a well known manner to eject castings from the ejector die 22. As in conventional machines of this type a movable die support member 16 is attached to a power means through a suitable toggle arrangement (not shown) whereby the movable support 16 and the ejector die 22 are moved into contact with and away from the cover die 18 in a well known manner. Further conventional features of the apparatus include a preferably cone-shaped opening 2S through the stationary die support 12 which extends into the cover die 18 and exposes a sprue 3l) through which an injection of molten metal is made into the die cavity (not shown).

On the rear side of the stationary support 12 and resting upon the base 10 is a furnace 32 lined with a suitable refractory material 34. A melting pot 36 is secured within the furnace 32 and heat is supplied thereto by a suitable burner 3S and a blower 40. Disposed within the melting pot 36 and submerged in a mass of molten metal 42 contained therein is a pressure chamber 44 which has integrally formed therewith a conventional gooseneck 46 containing therethrough a restricted conduit 47 from the pressure cylinder 44. The mouth of the gooseneck 48 includes a seat 50 which is in fluid-tight engagement with a nozzle 52 extending through the support 12 and engaging the sprue 30 of the cover die in duid-tight engagement. Preferably the pressure cylinder 44 is supported by a relatively heavy support structu-re S4 generally in the form of the letter A, hereinafter referred to as the A-frame. The A-frame is in turn slidably supported by a pair of spaced rods 56 and 58 as shown in FIGURE 2 which are bolted to the stationary die support 12 by means of brackets 60 and 62. To this end the A-frame is provided with openings 64 and 66 which receive therethrough the rods 56 and 58 respectively as shown in FIGURE 2. As seen in FIGURE 2, the pressure chamber 44 includes the flanged portions 68 which are clamped between an extending ridge 70 of the A-frame and the hardened metal wear plates 72 by means of the bolts '74,

The pressure cylinder 44 in itself is more less of conventional construction andas shown in FIGURES 1 and 2 it includes a cylindrical chamber having a line-r 76 therein, a shot piston 78 reciprocable therein and the gooseneck portion 46 extending from the base of the cylinder to a location above the molten metal where the seat 50 thereof may be -aligned with the nozzle 52. Openings 80 las shown in FIGURE 2 into the pressure cylinder are provided so that when the piston is in a .raised position as shown in FIGURES 1 and `2, molten metal will enter the shot cylinder by force of gravity. In the operation of the appara- Itus af-ter the molten metal has flowed linto the shot cylinder, the piston 78 is brought forcibly downwardly whereby the ports 80 are closed by the piston `and the molten metal is forced into the gooseneck through the restricted passage 47 thereof and hence onto .the nozzle 52 and thence to the die cavity (not shown) of the closed dies 18 and 22.

The pressure chamber 44 is held in a properly aligned and sealing relationship with respect to the sprue of the cover die by a centrally disposed means for yieldingly urging the A-frame 54 longitudinally along a line perpendicular to the nozzle 52 and the orifice or mouth 48 of the gooseneck. To this end, a yoke 82 is bolted to the ends of the rods 56 and 58. Formed integrally with the A- frame l54 `is a cylinder 84 which contains a compression spring, preferably a plurality of lBelleville-type springs 86 and a piston 88 in engagement with the Belleville springs `86. The piston `88 is attached to a connecting rod 90 which has la portion 92 threadably held within the yoke 82. It is readily apparent that pressure imposed by the piston 88 against the Belleville springs 86 will constantly urge the mouth of the gooseneck `48 against the nozzle 52.

The principal feature of this invention is the -coupling means by which the shot plunger is connected to its hydraulic loperating means. As shown in lFIGURES l and 2 the shot plunger 78 is attached to a connecting rod 94 by means of a special coupling 96 to to be hereinafter described more fully. The connecting rod 94 is in turn attached rto a hydraulic means 97 of a conventional type mounted on the A-frame 54 directly over the shot plunger and pressure cylinder.

The special coupling 96 is best shown in FIGURE 3. The coupling consists of a back half 98 and a front half consisting of an upper section 100 and a lower section 102. The back half '98 has cut in the upper part thereof a recess 104 for receiving one half of the bottom end of the connecting rod 94 having the annular groove 95 provided therein. The upper section 100 of the front half of the coupling similarly has -a recess 106 -cut therein to receive the other half of the connecting rod end 94. When assembled, the end of the connecting rod end is inserted in the recess 104 and the upper section of the back half 98 `and the front half 100 is bolted to the back half 98 by means of the bolts 108.

The lower portion of the back half 98 has a partially cylindrical recess 110 leading to a partially cylindrical recess 112 of greater diameter which in turn leads to a partially cylindrical recess 114 of still larger diameter. The recess 110 `is cut to snugly receive the shank end 116 of the shot plunger which is cylindrical in shape and the partially cylindrical portion 112 is cut to snugly receive the enlarged cylindrical head 118 of the shot plunger.

The lower section 102 is hinged to the back half 98 by the integrally formed hinge means including the apertured projections 120, the recesses 122, the openings 124 and the pin 126. Within the lower half 102 there is provided the cylindrical recesses 128, 130 and 132 corresponding respectively `in configuration to the back half recesses 110, 112 and 114. Within the recess 132 there is positioned a cylindrical block 134 preferably permanently secured therein as by soldering -or brazing which will fill the cylindrical space formed by the recesses 114 and 132 when the lower half 102 is moved into a closed position with respect to the back section 98 as shown in FIGURE 1 to prevent any vertical movement of the head 118 with respect to the coupling. A latch means 136 is provided to hold the coupling in a closed -and locked position.

The coupling described above serves an important function in the installation of the machine since, as may be observed in FIGURE 2, when the lower portion 102 of the coupling is opened and the cylindrical block 134 is therefore removed from the recess 114, the piston plunger shank head 118 may be raised a sufficient distance to permit `the piston 78 to clear the top of the cylinder liner 76 and readily permit its removal from the apparatus. In the installation of the piston, on the other hand, the piston is readily inserted into the pressure cylinder and the shank head 118 readily inserted in the enlarged recess 112. In :this position the alignment of the piston with respect to the coupling 98 may be readily observed.

Another important feature of the coupling 98 as is apparent in FIGURES 1, 2 and 4 is in means associated therewith which cooperate with the A-frame 54 to hold the coupling 96 Iin a fixed position so that the plunger 78 may be installed or removed. To this end, the coupling 96 includes horizontally extending wing projections 138 and 140 as best shown in FIGURES 2 and 4. The coupling may be rotated to engage the abutments 142 and 144 of the A-frame whereby the shot plunger is mechanically locked in a retracted or upward position as is shown in FIGURE 2. As shown in FIGURES 2 and 4, the laterally extending portions 142 and 144 are provided on two opposite sides only of the A-frame and when the coupling is in a closed position, the lateral projections 138 and 140 are also provided on only two opposite sides of the coupling. It is apparent that a movement of the coupling to a position shown in FIGURE 4 causes the coupling projections to extend over the A-frame projections 142 and 144 and the coupling is in a position to be opened whereas when the coupling is rotated as indicated by the broken lines in lFIGURE 4, the coupling Iis free to reciprocate between the projections 142 and 144 of the A- frame. Rotation of the coupling may be accomplished by a Spanner wrench or other suitable means. This provision for locking the coupling as described -xes the location of the mechanism so that piston installation, inspection and alignment and servicing can be readily performed.

While the embodiments of the invention is disclosed herein constitute preferred forms, it is to be understood that other forms may be adopted without departing from the spirit of the invention.

I claim:

1. In a die casting machine the combination comprising a pressure chamber and a plunger operatively disposed therein and including a shank terminating in an enlarged end, a frame member mounted over said pressure chamber supporting said pressure chamber, a hydraulic plunger operating means mounted on said frame over said pressure chamber in axial alignment therewith and having a depending connecting rod, and split connector means rigidly connecting said rod to said plunger in axially aligned relationship, said connector means having a passage therein comprising a first portion slidably receiving said shank therein, a second portion adjacent said first portion and of greater radial thickness than said first portion slidably and snugly receiving said enlarged end, a third portion adjacent said second portion having a radial thickness larger than said second portion and a removable insert snugly within said third portion and abutting said enlarged end, thereby preventing vertical movement of said enlarged end into the said third portion, said insert being removable only when said split connector means is opened.

2. In a die casting machine the combination comprising a pressure chamber and a plunger operatively disposed therein and including a shank terminating in an enlarged end, a frame member mounted over said pressure chamber supporting said pressure chamber, a hydraulic plunger operating means mounted on said frame over said pressure chamber in axial alignment therewith and having a depending connecting rod, connector means rigidly connecting said rod to said plunger in axially aligned relationship, said connector means having a passage therein comprising a first portion slidably receiving said shank therein, a second portion adjacent said iirst portion and of greater thickness than said first portion slidably and snugly receiving said enlarged end, a third portion adjacent said second portion having a thickness larger than said second portion and a removable insert within said third portion for preventing vertical movement of said enlarged end within the said third portion, an upper abutment surface associated with said frame below said hydraulic means, and a lower abutment surface on and extending from one side of said connector means adapted to engage said upper abutment surface when said connector is rotated to a predetermined position, said connector means being adapted to avoid said upper abutment surface when said connector is rotated from said predetermined position.

3. ln a `die casting machine of the hot chamber type the combination comprising a gooseneck unit including a pressure chamber and a plunger operatively disposed therein and including a shank terminating in an enlarged end, an A-frame mounted over said pressure chamber supporting said gooseneck unit, hydraulic plunger operating means mounted on said A-fra-me over said pressure chamber in axial alignment therewith and having a depending connecting rod, and lsplit connector means rigidly connecting said connecting rod to said plunger in axially aligned relationship, said connector means having an axial passage axially therethrough comprising a first portion slidably receiving said shank therein, a second portion adjacent said first portion and of greater radial thickness than said first portion slidably and snugly receiving said enlarged end, a third portion adjacent said second portion having a radial thickness larger than said second portion and a removable insert snugly within said third portion and abutting said enlarged end, thereby preventing vertical movement of said enlarged end into the said third portion, said insert being removable only when the split connector means is opened.

4. Die casting apparatus including stationary support means, a cover die mounted on one side thereof, movable die support means having an ejector die mounted thereon and being adapted for moving said ejector die toward and away from said cover die, horizontal support means iixed to the opposite side of said stationary support, an A-frame slidably mounted on said horizontal support means, a gooseneck unit including a pressure chamber and a plunger operatively disposed therein and including a shank terminating in an enlarged end, said gooseneck unit being supported by said A-frame in communication with said cover die, hydraulic operating means mounted on said A-frame over said pressure chamber in axial alignment therewith and having a depending connecting rod, and split connector means rigidly connecting said connecting rod to said plunger in axially aligned relationship, said connector means having an axial passage therein comprising a first portion slidably receiving said shank therein, a second portion adjacent said first portion and of greater radial thickness than said first portion slidably and snugly receiving said enlarged end, a third portion adjacent said second portion having a radial thickness larger than said second portion and a removable abutment snugly within said third portion and abutting said enlarged end, thereby preventing vertical movement of said enlarged end into` the said third portion, said insert being removable only when said split connector means is opened.

5. in a die casting machine of the hot chamber type the combination comprising a gooseneck unit including a pressure chamber and a plunger operatively disposed therein and including a shank terminating in an enlarged end, an A-frame mounted over said pressure chamber supporting said gooseneck unit, hydraulic plunger operating means mounted on said A-frame over said pressure chamber in axial alignment therewith and having a depending connecting rod, connector means rigidly connecting said connecting rod to said plunger in axially aligned relationship, said connector means having a passage therein comprising a first portion slidably receiving said shank therein, a second portion adjacent said first portion and of greater thickness than said first portion slidably and snugly receiving said enlarged end, a third portion adjacent said second portion having a thickness larger than said second portion and a removable insert within said third portion for preventing vertical movement of said enlarged end within the said third portion, an upper abutment surface associated with said A-frame Ibelow said hydraulic means, and a lower abutment surface on and extending from one side of Said connector means adapted to engage said upper abutment when said connector is rotated to a predetermined position.

6. Die casting apparatus including stationary support means, a cover die mounted on one side thereof, movable die support means having an ejector die mounted thereon and being adapted for moving said ejector die toward and away from said cover die, horizontal support means fixed to the opposite side of said stationary support, an A-frame slidably mounted on said horizontal support means, a gooseneck unit including a pressure chamber and a plunger operatively disposed therein and including a shank terminating in an enlarged end, said gooseneck unit being supported by said A-frame in communication with said cover die, hydraulic operating means mounted .on said A-frame over said pressure chamber in axial alignment therewith and having a depending connecting rod, connector means rigidly connecting said co-nnecting rod to said plunger in axially aligned relationship, said connector means having a passage therein comprising a first portion slidably receiving said shank therein, a second portion adjacent said iirst portion and of greater thickness than said iirst portion slidably ard snugly receiving said enlarged end, a third portion adjacent said second portion having a thickness larger than said second portion aud a removable abutment within said third portion for preventing vertical movement of said enlarged end within the said third portion, Vand upper abutment surface associated with said A-frame below said hydraulic means, and a lower abutment means yon one side of said connector means adapted to engage said upper abutment surface when said connect-or is rotated to a predetermined position, said third portion and said insert being of sufficient height to permit insertion of said plunger into said pressure chamber to a sufficient depth to `observe alignment of said plunger relative to said connecting rod and said pressure chamber when said upper abutment is in engagement with said lower abutment.

7. Die casting apparatus including stationary support means, a cover die mounted on one side thereof, movable die support means having an ejector die mounted thereon and being adapted for moving said ejector die toward and away from said cover die, horizontal support means fixed to the opposite side `of said stationary support, an A-frame slidably mounted on said horizontal support means, a gooseneck unit including a pressure chamber and a plunger operatively disposed therein and including a shank termina-ting in an enlarged end, said gooseneck unit being supported by said A-frame in communication with said cover die, hydraulic operating means mounted on said A-frame over said pressure chamber in axial alignment therewith and having a depending connecting rod, and split connector means rigidly connecting said connecting rod to said plunger in axially aligned relationship, said connector means having an axial passage therethrough comprising a first portion slidably receiving said shank therein, a second portion adjacent said first portion and of greater radial thickness than said first portion slidably and snugly receiving said enlarged end, a third portion adjacent said second portion having a radial thickness larger than said second portion and a fourth portion Xedly receiving said connecting rod end and a removable abutment snugly within said third portion and abutting said enlarged end, thereby preventing vertical movement `of said enlarged end into the said third portion.

8. In a die casting machine the combination comprising a pressure chamber and a plunger operatively disposed therein and including a shank terminating in an enlarged end, a frame member mounted over said pressure chamber supporting said pressure chamber, a hydraulic plunger operating means mounted .on said frame over said pressure chamber in axial alignment therewith and having a depending connecting rod, connector means rigidly connecting said rod to said plunger in axially aligned relationship, said connector means comprising an 'upper and lower section, said lower section comprising a stationary portion attached to said upper section and a movable portion hinged Ito said lower stationary portion whereby said movable portion may be moved between open and closed positions, said lower section when in a closed position including a passage therein equally proportioned between said stationary and movable portions, said passage including a first lowermost portion sldably receiving said shank therein, a second portion adjacent said first portion and of greater thickness than said lirst portion sldably and snugly receiving said enlarged end, a third portion adjacent said second portion having a thickness larger than said second portion and an insert within said third portion for preventing vertical movement of said enlarged end within said third portion, an upper abutment associated with said frame below said hydraulic means, and a lower abutment surface on and extending from one side of said connector means adapted to engage said upper abutment when said connector is rotated to a predetermined position, said connector means being adapted to avoid said upper abutment when said connector is rotated from said predetermined position.

9. Die casting apparatus including stationary support means, a cover die mounted on one side thereof, movable die support means having an ejector die mounted thereon and being adapted for moving said ejector die toward and away from said cover die, horizontal support means lixed to the opposite side of said stationary support, an A-frame sldably mounted on said horizontal support means, a gooseneck unit including a pressure chamber and a plunger operatively disposed therein and including a shank terminati-ng in an enlarged end, said gooseneck unit being supported by said A-frame in communication with said cover die, hydraulic operating means mounted on said A-frame over said pressure chamber in axial alignment therewith and having a depending connecting rod, connector means rigidly connecting said connecting `rod to said plunger in axially aligned relationship, said connector means comprising an upper and lower section, said lower section comprising a stationary portion attached to said upper section and a movable porti-on hinged to said lower stationary portion whereby said movable portion may be moved between open and closed positions, said lower section when in a closed position including a passage equally proportioned between said stationary and movable portions, said passage including a first lowermost portion sldably receiving said shank therein, a second portion adjacent said tirst portion and of -gcrater thickness than said first portion sldably and snugly receiving said enlarged end, a third portion adjacent said seconnd =portion having a thickness larger than said second portion `and an insert within said third portion for preventing vertical movement of said enlarged end within said third portion, an upper abutment surface associated with said A-frame below said hydraulic means, and a lower abutment surface on and extending from one side of said connector means and being adapted to engage said upper abutment surface when said connector is rotated to a predetermined position, said third porti-on and said insert being of sufficient height to permit insertion of said plunger into said pressure chamber to a suliicient depth to observe alignment of said plunger relative to said connecting rod and said pressure chamber when said upper abutment surface is in engagement with said lower abutment surface.

References Cited by the Examiner UNITED STATES PATENTS 120,686 1871 Weston 287-111 448,395 1891 Wheeler 287-91 1,073,776 9/1913 Neville 287-111 1,406,229 2/1922 schneider 287-111 1,431,287 10/1922 Brown 287-91 1,806,687 5/1931 Hoover 287-111 1,931,489 10/1933 During 22-70 XR 1,944,141 1/1934 Stidd 287-108 2,108,080 2/1938 Schultz et al. 22-70 XR 2,393,588 1/1946 Cherry et al. 22-70 2,485,526 10/1949 Bennett 22-70 2,522,866 9/1950 Gash 22-70 2,656,576 10/1953 Schwartz 22-70 3,032,360 5/1962 Woodings 287-108 3,073,635 1/1963 Schaefer 287-108 I. SPENCER OVERHOLSER, Primary Examiner.

MARCUS U. LYONS, Examiner. 

1. IN A DIE CASTING MACHINE THE COMBINATION COMPRISING A PRESSURE CHAMBER AND A PLUNGER OPERATIVELY DISPOSED THEREIN AND INCLUDING A SHANK TERMINATING IN AN ENLARGED END, A FRAME MEMBER MOUNTED OVER SAID PRESSURE CHAMBER SUPPORTING SIAD PRESSURE CHAMBER, A HYDRAULIC PLUNGER OPERATING MEANS MOUNTED ON SAID FRAME OVER SAID PRESSURE CHAMBER IN AXIAL ALIGNMENT THEREWITH AND HAVING A DEPENDING CONNECTING ROD, AND SPLIT CONNECTOR MEANS RIGIDLY CONNECTING SAID ROD TO SAID PLUNGER IN AXIALLY ALIGNED RELATIONSHIP, SAID CONNECTOR MEANS HAVING A PASSAGE THEREIN COMPRISING A FIRST PORTION SLIDABLY RECEIVING SAID SHANK THEREIN, A SECOND PORTION 